1. Field of Invention
The invention relates to an electronics device, and more specifically relates to an integrated circuit that is incorporated into a host electronic device that allows for easy testing of a Power Management Unit that is integrated with another electronics component (such as a Baseband Processor).
2. Related Art
Wireless communication devices, such as cellular telephones to provide an example, are becoming commonplace in both personal and commercial settings. The wireless communication devices provide users with access to all kinds of information. For example, a user can access the internet through an internet browser on the device, download miniature applications (e.g., “apps”) from a digital marketplace, send and receive emails, or make telephone calls using a voice over internet protocol (VoIP). Consequently, wireless communication devices provide users with significant mobility, while allowing them to remain “connected” to communication channels and information.
Wireless communication devices communicate with one or more other wireless communication devices or wireless access points to send and receive data. Typically, a first wireless communication device generates and transmits a radio frequency signal modulated with encoded information. This radio frequency signal is transmitted into a wireless environment and is received by a second wireless communication device. The second wireless communication device demodulates and decodes the received signal to obtain the information. The second wireless communication device may then respond in a similar manner. The wireless communication devices can communicate with each other or with access points using any well-known modulation scheme, including simple amplitude modulation (AM), simple frequency modulation (FM), quadrature amplitude modulation (QAM), phase shift keying (PSK), quadrature phase shift keying (QPSK), and/or orthogonal frequency-division multiplexing (OFDM), as well as any other communication scheme that is now, or will be, known.
Over the years, there has been increasing effort to make wireless communication devices more portable. However, because of the increased functionality of modern wireless communication devices, wireless communication devices are becoming increasingly complex. Therefore, one way to reduce the size of wireless communication devices is by combining multiple components onto a single integrated circuit (i.e., chip). For example, Broadcom Corporation has made significant advances recently in combining a power management unit (PMU) with another component (such as a baseband processor) onto a single chip. However, combining the PMU with another component significantly reduces the number of pins that can be designated for the PMU. This requires that functional signals designated for the PMU be sent through the other component, and also makes testing the PMU particularly difficult. Because the PMU is a particularly sensitive component, it is necessary to ensure that signals coming into the PMU from the other component are at satisfactory voltage levels in order to protect the PMU.
Consequently, there is a need for an integrated circuit, which includes the PMU combined with another component, that allows for effective and safe testing of the PMU, as well safe communication between the PMU and the other component. Further aspects and advantages of the invention will become apparent from the detailed description that follows.
The invention will now be described with reference to the accompanying drawings. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the reference number.